She says she has been gainfully employed the past months cleaning "among the Jews", and here we have a Jewish Socialist club in need of cleaning. I don't see it as farfetched. And if that's the case, then it may have been misinterpreted why she was there by someone at the club and it escalated to fatal, or maybe she was there to meet a Jewish man socially.

I put about equal weight on them as possibilities...although I cant say probability based on known data.

I think you've got the balance spot on with that. If, as seems to have been the case, she was well known to the local Jewish community why would she need to wait around outside the Club, whatever her reason for being there?